Capturing the distinction between task and device errors in a formal model of user behaviour

In any complex interactive human-computer system, people are likely to make errors during its operation. In this paper, we describe a validation study of an existing generic model of user behaviour. The study is based on the data and conclusions from an independent prior experiment. We show that the current model does successfully capture the key concepts investigated in the experiment, particularly relating to results to do with the distinction between task and device-specific errors. However, we also highlight some apparent weaknesses in the current model with respect to initialisation errors, based on comparison with previously unpublished (and more detailed) data from the experiment. The differences between data and observed model behaviour suggest the need for new empirical research to determine what additional factors are at work. We also discuss the potential use of formal models of user behaviour in both informing, and generating further hypotheses about the causes of human error

CBR and MBR techniques: review for an application in the emergencies domain

The purpose of this document is to provide an in-depth analysis of current reasoning engine practice and the integration strategies of Case Based Reasoning and Model Based Reasoning that will be used in the design and development of the RIMSAT system. RIMSAT (Remote Intelligent Management Support and Training) is a European Commission funded project designed to: a.. Provide an innovative, 'intelligent', knowledge based solution aimed at improving the quality of critical decisions b.. Enhance the competencies and responsiveness of individuals and organisations involved in highly complex, safety critical incidents - irrespective of their location. In other words, RIMSAT aims to design and implement a decision support system that using Case Base Reasoning as well as Model Base Reasoning technology is applied in the management of emergency situations. This document is part of a deliverable for RIMSAT project, and although it has been done in close contact with the requirements of the project, it provides an overview wide enough for providing a state of the art in integration strategies between CBR and MBR technologies.Postprint (published version

A formal framework for the specification of interactive systems

We are primarily concerned with interactive systems whose behaviour is highly reliant on end user activity. A framework for describing and synthesising such systems is developed. This consists of a functional description of the capabilities of a system together with a means of expressing its desired 'usability'. Previous work in this area has concentrated on capturing 'usability properties' in discrete mathematical models. We propose notations for describing systems in a 'requirements' style and a 'specification' style. The requirements style is based on a simple temporal logic and the specification style is based on Lamport's Temporal Logic of Actions (TLA) [74]. System functionality is specified as a collection of 'reactions', the temporal composition of which define the behaviour of the system. By observing and analysing interactions it is possible to determine how 'well' a user performs a given task. We argue that a 'usable' system is one that encourages users to perform their tasks efficiently (i.e. to consistently perform their tasks well) hence a system in which users perform their tasks well in a consistent manner is likely to be a usable system. The use of a given functionality linked with different user interfaces then gives a means by which interfaces (and other aspects) can be compared and suggests how they might be harnessed to bias system use so as to encourage the desired user behaviour. Normalising across different users anq different tasks moves us away from the discrete nature of reactions and hence to comfortably describe the use of a system we employ probabilistic rather than discrete mathematics. We illustrate that framework with worked examples and propose an agenda for further work

The evaluation of dynamic human-computer interaction

This thesis describes the development and evaluation of a theoretical framework to account for the dynamic aspects of behaviour at the Human-Computer Interface (HCIF). The purpose behind this work is to allow for the consideration of dynamic Human-Computer Interaction (HCI) in the design of interactive computer systems, and to facilitate the generation of design tools for this purpose. The work describes an example of a design tool which demonstrates how designers of interactive computer systems may account for some aspects of the dynamics of behaviour, involved with the use of computers, in the design of new interactive systems. The thesis offers empirical and literary evidence to support the validity of the dynamic factors governing the interaction of humans with computers

Evaluating usability evaluation methods for location-­aware interactive systems in contextually rich environments.

PhDIn this research we investigate the evaluation of usability evaluations methods (UEMs). In particular we are concerned with evaluating their suitability for the evaluation of location-­‐ aware systems. Not all approaches for the evaluation of UEMs have been extensively validated for such types of dynamic interaction, while their application is not clearly documented. We overview the strengths of the current approach and suggest how to improve them. We examine navigation systems as examples for issues with location-­‐aware systems in a contextually rich environment. The setting is very different to a traditional desktop-­‐based application. Take the use of the navigation device for example. It is a secondary task; the primary task is to safely drive the car. The interface is continuously changing to adapt to the current location of the user. The user navigates in a complex dynamic environment encompassing various stimuli and unpredictable external factors. We present in the thesis a methodological and systematic way to approach the evaluation of UEMs. A comparative study of analytical and empirical techniques was carried out, to assess them in identifying usability problems within both static and dynamic contexts of use. Four analytical methods (CW, UAN, EMU, and Design Guidelines) and one empirical were compared. In this thesis, we validate the existing classification scheme of Blandford et al. (2008) and highlight relevant issues. We present an alternative systematic approach building on this scheme (CoHUM), and its shortcomings with dynamic systems. We show how a rigorous and systematic error analysis identifies phenotypes as the outcome of empirical techniques, whilst genotypes are the outcome of analytical techniques. Finally, we present new dimensions that previous literature had not identified for the evaluation of UEMs. This research will help future researchers by providing them with a stronger methodological approach for comparing UEMs and, in particular, categories of UEMs

Applicability of HCI Techniques to Systems Interface Design

PhDThis thesis seeks to identify reasons why HCI techniques are unsuitable for application in real world design projects. User-oriented systems design and evaluation require that many considerations such as the psychology of users, the applications and target tasks be born in mind simultaneously. A selection of influential HCI design and evaluative techniques from HCI research literature are reviewed and characterised in terms of their analytic scope. Two studies of systems designers' approaches to user-oriented design and evaluation were carried out in order to gain a clearer picture of the design process as it occurs in applied and commercial projects. It was found that designers frequently lack adequate information about users, carrying Out, at best, informal user-evaluations of prototypes. Most notably HCI design and evaluative techniques, of the type common in the literature, are not being used in applied and commercial design practice. They seem to be complex, often limited in scope, and possessed of inadequate or unrepresentative views of the design process within which they might be applied. It was noted that design practice is highly varied with only a small number of common goal directed classes of activity being identified. These together with observed user-oriented information sources and design constraints provide a useful schema for viewing applied and commercial design practice. A further study of HCI specialists' practice in commercial environments was undertaken, in order to identify particular user-oriented design approaches and HCI techniques suitable for application in practice. The specialists were able to describe desirable, and undesirable properties of the techniques they used which made it possible to identify a list of specific desirable features for HCI techniques. A framework for assessing applicability of HCI techniques was developed from the findings of the thesis. This is demonstrated using an example project from the design studies and may prove valuable in supporting design, evaluation, critiquing and selection of HCI techniques

Use of nonintrusive sensor-based information and communication technology for real-world evidence for clinical trials in dementia

Cognitive function is an important end point of treatments in dementia clinical trials. Measuring cognitive function by standardized tests, however, is biased toward highly constrained environments (such as hospitals) in selected samples. Patient-powered real-world evidence using information and communication technology devices, including environmental and wearable sensors, may help to overcome these limitations. This position paper describes current and novel information and communication technology devices and algorithms to monitor behavior and function in people with prodromal and manifest stages of dementia continuously, and discusses clinical, technological, ethical, regulatory, and user-centered requirements for collecting real-world evidence in future randomized controlled trials. Challenges of data safety, quality, and privacy and regulatory requirements need to be addressed by future smart sensor technologies. When these requirements are satisfied, these technologies will provide access to truly user relevant outcomes and broader cohorts of participants than currently sampled in clinical trials